British electric multiple units
[6] In 1898, the deep-level Waterloo and City Railway opened with EMUs, a central third rail providing traction current at 500 V to 530 V DC.
[9] The current for the two motor cars could be controlled from either driving cab, but the Board of Trade became concerned about the fire risk presented by the 11 power cables carried on the roof of the train and barred installation of similar systems in deep-level tubes.
[16] This electro-magnetic system was developed in Britain by British Thomson-Houston (BTH) and first used in Europe in 1902 on the Central London Railway when it changed over to EMU operation to solve a design problem with its locomotives.
[20] In London, the Great Northern & City Railway was a 3+1⁄2 miles (5.6 km) underground line from Moorgate to Finsbury Park.
[22] The North Eastern Railway (NER) began using EMUs between New Bridge Street and Benton on 29 March 1904 and from 25 July 1904 over a circular route between Newcastle Central and Tynemouth, electrified with a third rail at 600 V DC (see Tyneside Electrics).
Twenty trains with BTH equipment were ordered for the Hammersmith & City line, jointly operated by the Great Western Railway and the Met.
Accommodation in open saloons was accessed by end platforms protected by lattice gates and power was collected from a 550-600 V DC four-rail system and controlled with BTH equipment.
[32] In 1907 the London & North Western Railway (L&NWR) obtained permission for a pair of extra tracks for suburban services beside its main line from Euston to Watford.
Delayed by the World War I, the first electric service ran in 1914 from Earl's Court to Willesden Junction, using borrowed District Railway trains.
[27] Using converted steam-hauled carriages, three-car units ran with a trailer between two driving motor cars with Westinghouse electrical equipment.
[48] On suburban services, the lack of a driving position in the unpowered trailer was proving inflexible and in the early 1940s a four-car unit was built.
[53] In 1938 Q Stock was built by replacing the District line EMU wooden trailers with new steel ones and equipping the trains with air-operated sliding doors and electro-pneumatic brakes.
[57] In 1938, the Tyneside Electrics third rail DC system was extended to South Shields and new EMUs were bought to allow for service expansion.
[61] Some pre-war capital investment schemes that had stopped upon the outbreak of hostilities were restarted, such as 1,500 V DC electrification of the Manchester–Sheffield–Wath route and the Great Eastern suburban railways.
[citation needed] The London to Shenfield route opened in 1949 with three-car EMUs with air-operated doors that collected traction current with a single diamond-shaped pantograph.
[75] For the deep-level tubes the unpainted aluminium 1959 stock was developed to replace pre-war designs, and entered service on the Piccadilly line and later on the Central.
[citation needed] Bulleid-bodied production switched to the standard BR Mark 1 body in 1954, when two-car units were built to lengthen trains to ten cars on Kent suburban routes.
At first it was intended to fit bus engines, but the line was electrified with the third-rail DC system and the cars overhauled and formed into three- and four-car units.
[94] In the late 1960s, British Railways adopted the Total Operations Processing System (TOPS) to manage its rolling stock.
[99] In the mid-1990s, new trains, which featured regenerative braking and allowed the withdrawal of guards, were introduced on London Underground's Northern and Jubilee lines.
[102] The DC Class 455 for inner-suburban duties in South London were built in the early and mid-1980s with recovered traction motors and equipment.
[105] Class 442 5Wes was built in 1988 for the DC South West Main Line from London Waterloo to Southampton, Bournemouth, Poole and Weymouth.
New trains were introduced based on German Stadtbahnwagen B light rail units and power was taken from an overhead line at 1500 V DC.
To ensure flexibility with leasing arrangements electric multiple units are specified to be able to be modified to run on both the 25 kV AC and 750 V DC systems.
[124] Introduction was protracted on both routes with problems such as cab and control equipment so the HSE extended the use of Mark 1 based rolling stock until 31 December 2004 with the proviso: "... that any Mark 1 rolling stock operated by the TOCs after 31 March 2003 must form part of a train fully fitted with a train protection system.
[123] From 2000 to 2005 Virgin Trains modernised the West Coast Main Line with Alstom's Class 390 125 mph (201 km/h) capable nine-car units.
[139] In December 2003, approval was given to run domestic services on the planned Channel Tunnel Rail Link (CTRL) (now High Speed 1) from Kent.
[144] In 2011, new trains were introduced on London Underground's Victoria line with IGBT driven AC asynchronous electric motors and regenerative braking.
[151] An economic case can be made for replacing DC electrification with AC when the trackside equipment reaches the end of its life[152] as long as the rolling stock is capable of conversion[151] and costly infrastructure works are not needed.
[156] In the 2012, High Level Output Specification the Department of Transport asked the rail industry to present plans to convert the line from Basingstoke to Southampton Docks by 2019 as part of a new electrified route from North to South and as a pilot conversion project.
